BACKGROUND/OBJECTIVES: We investigated if breastfeeding duration and current dietary patterns (DP) were associated with glucose and lipid metabolism biomarkers in women from the Nutritionist's Health Study. SUBJECTS/METHODS: This is a cross-sectional analysis of 200 healthy undergraduates and nutrition graduates aged ≤45 years. Total [<6; ≥6 months] and predominant [<3; ≥3 months] breastfeeding were recalled using questionnaires. Diet were assessed using a food frequency questionnaire. DP obtained by factor analysis by principal component were categorized into tertiles of adherence (T1 = reference). Glucose and lipid biomarkers were categorized into tertiles (T1 + T2 = reference). Logistic regression was applied considering minimal sufficient adjustment recommended by directed acyclic graphs. RESULTS: Median (interquartile range) age and BMI were 23.0 (20.0; 28.5) years and 22.6 (20.7; 25.4) kg/m2, respectively. Mean ± SD values of glucose, LDL-c and HDL-c were 82.0 ± 9.0, 101.1 ± 29.6 and 54.4 ± 12.4 mg/dL, respectively. Women breastfed for <6 months had higher chance of being classified into T3 of insulin (OR = 2.87; 95%CI = 1.28-6.40). Predominant breastfeeding < 3 months was associated with insulin levels (OR = 2.27; 95%CI = 1.02-5.02) and HOMA-IR (OR = 2.36; 95%CI = 1.06-5.26). Breastfeeding was not associated with lipids. The Processed pattern was directly associated with LDL-c (T3: OR 6.08; 95%CI 1.80-20.58; P-trend = 0.004), while the Prudent pattern was inversely associated with LDL-c (T3: OR 0.26; 95%CI 0.08-0.87; P-trend = 0.029) and LDL-c/HDL-c ratio (T3: OR 0.28; 95%CI 0.08-0.97; P-trend = 0.046). CONCLUSION: Early feeding could be a protective factor against insulin resistance development, while current DP were associated with lipid profile. This evidence indicates that from early life until early adulthood, dietary habits might influence women's cardiometabolic risk profile.